Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must disclose behavioral traits. 'Prepare' suggests a staged mutation but doesn't explain side effects, whether it's a dry run, or what the response contains. For a mutation-related tool with zero annotation coverage, this is a significant gap.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single sentence with no wasted words. It is concise and front-loaded with the core purpose. However, it is so brief that it borders on under-specification, which slightly lowers the score.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema and no annotations, the description should explain the prepare/confirm workflow and any expected outcomes. It doesn't. An agent cannot tell if this operation is reversible, what it returns, or how it relates to the confirm sibling. The description is minimal and leaves critical context missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 33% (customer_id has a description). The description adds no detail about campaign_id or amount_micros, and doesn't clarify units or validation. It fails to compensate for the low schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a clear action: 'Prepare updating a campaign daily budget.' It identifies the resource (campaign daily budget) and the operation (prepare). It distinguishes from siblings like google_ads_budget_update_confirm (which would confirm) and google_ads_bidding_update_prepare (different budget type), though it doesn't explicitly name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives. The sibling list includes many prepare/confirm pairs, and the description doesn't explain the two-phase pattern or when a prepare step is needed. The agent is left to infer that 'prepare' precedes a confirm step.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.